Um, hammers are a scam, too, I think. Show me research demonstrating they have to look like that! There are two points, both missed by the author, to a good office chair.

Firstly, adjustability. The chair is not ergonomic per se, but it allows for a massive amount of adjustment so everyone can get what they need. You can get HM chairs in various sizes, by the way. Secondly, durability. I sat on an HM for 6 years or so without it showing literally any wear. I have a cheap office chair at home that looks like crap after 4.